Unix Technical Digest V3 #1

[Heiby]

Unix Technical Digest       Tue, 14 Jan 86       Volume  3 : Issue   1

Today's Topics:
                            Administrivia
                            Error utility
                         Problem with "make"
                        tcp/ip over tty lines
             Wanted: mail broadcast and cleanup programs
----------------------------------------------------------------------

Date: Tue, Jan 14 12:17:17 CST 1986
From: Ron Heiby <unix-request at cbosgd.UUCP>
Subject: Administrivia

This is the first installment of the Moderated Unix Technical Digest
Volume 3.  It is also the first installment to appear on mod.os.unix
instead of mod.unix.  Submissions for the list should still be sent
to unix at cbosgd.UUCP.

I apologize for the large delay recently in forwarding submissions.
There have been very few (they are below) and my job has been changing
recently and taking much of my time.  I expect to be able to do much
better, now.

Volume 1 contained issues 1 through 55.  Volume 2 contained issues
1 through 21.  Back issues can be mailed if you missed a few.

Thanks much.  Ron.

------------------------------

Date: Mon, 28 Oct 85 16:19:34 CST
From: Stan Barber <neuro1!sob>
Subject: Error utility

Have you error gotten just an error number from some program (because
the writer didn't use perror) and wanted to know quickly what it
was about?

Here is a quick utility to help you.

(maybe this is too obvious, but I thought it might help the novice)
--------------- NOT A SHELL ARCHIVE --------------------------------
/* error -- generates the error produced by errno set to
 * a particular number
 * $Log:	error.c,v $
 * Revision 1.1  85/10/28  16:11:49  sob
 * Initial revision
 * 
 *
 */
static char rcsid[] = "$Header: error.c,v 1.1 85/10/28 16:11:49 sob Exp $";
#include <stdio.h>

extern int errno;
extern int sys_nerr;
extern char *sys_errlist[];

main(argc,argv)
	int argc;
	char * argv[];
{

	if (argc == 1)
		{
			printf("Usage: %s error-number\n",argv[0]);
			exit(-1);
		}

	while (--argc>0) {
		
		errno = atoi(*++argv);
		if (errno >= sys_nerr)  
			printf("Error number %d: Undefined Error\n",errno);
		else
			printf("Error number %d: %s\n",errno,sys_errlist[errno]);
	}
	
	exit(0);
}

------------------------------

Date: Wed, 11 Dec 85 08:16:52 -0100
From: Per Westerlund <seismo!enea!chalmers!per>
Subject: Problem with "make"

I have encountered a slight problem. It is a problem with "make".
"Make" does not behave the way I think it should. Instead of insulting
You all with elementary explanations of what the problem is, I will give
You an example to try on Your own. If this turns out to be yet another
case of "It's not a bug, it's a feature." I wil have to apologize.
Anyway, here it is. (The problem manifests on both Sys Vr2, VAX BSD4.2
and SUN 1.1.)

Exampel:

1)	Make an empty directory and "cd" to it.

2)	Create a file called "a.x" an a suitable way, it doesn't
	matter what content it has.

3)      Copy the the part of the message between the dotted lines to a
	file called "Makefile".

-----------------------------------------------------------------
.SUFFIXES:
.SUFFIXES: .z .y .x

.x.z:
	@echo "$*.x -> $*.z"

.x.y:
	@echo "$*.x -> $*.y"

.y.z:
	@echo "$*.y -> $*.z"

a.z:

#not_used: a.y

-----------------------------------------------------------------

	(The interesting thing is what happends when the '#' is removed.)

4)	Run make and observe what happends.

5)	Edit "Makefile" and remove the #-sign from the line that
	starts: "#not_used: ...".

6)	Repeat 4) and observe the difference.

Why does this happen, and how do I circumvent/fix the problem?


			Per Westerlund
			perw at holtec.UUCP

------------------------------

Date: Mon, 2 Dec 85 17:51:12 mst
From: ingham <ingham!cmcl2!lanl!unmc at cc.unm>
Subject: tcp/ip over tty lines

Has anybody out there got any experience using tcp/ip over tty lines?  I would
appreciate any hints, pointers, or whatever.  We are running Ultrix v1.1 and
also have 4.2bsd available.

Thanks,
Kenneth Ingham, UNM Computing Center, Albuquerque, NM 87131, 505-277-8044

    ~{pur-ee!purdue,ucbvax!lbl-csam,philabs!cmcl2}!lanl!unmc!ingham
    ~{convex,ucbvax,gatech,csu-cs,anl-mcs}!unmvax!unmc!ingham

------------------------------

Date: Sun, 29 Dec 85 14:50:22 est
From: allegra!phri!roy (Roy Smith)
Subject: Wanted: mail broadcast and cleanup programs

	I'm looking for a simple way to send mail to every "real" account
on my (4.2 bsd) system.  By "real" I mean accounts that people use; not
uucp logins and the like.  Posting to local.general won't work because far
too many people don't read news.  A normal mailing list is no good either
because the list changes too often; maintaining it would be a royal pain.

	Once I plaster the machine with junk mail, it would be nice to be
able to go through the spool area and clean out old stuff (some people
don't read their mail and it just piles up).  Doing "find -mtime +30" isn't
any good; I don't want to find people who don't get mail, I want to find
those who don't read it.  Idealy something that could parse the mail
headers and just excise out the old letters like expire would be nice.

Roy Smith <allegra!phri!roy>
System Administrator, Public Health Research Institute
455 First Avenue, New York, NY 10016

------------------------------

End of Unix Technical Digest
******************************
-- 
Ron Heiby	usenet at cuae2.UUCP	(via ihnp4)
AT&T-IS, /app/eng, Lisle, IL	(312) 810-6109